This video goes ridiculously in-depth on the subject of 10 particular models and brands of popular NiMH cells. It covers my recommendations, as well as an extensive dive into my testing methodology.
Downloads
As promised, here’s the spreadsheet that I mentioned in the video. Both links are to the same document, just in two different formats.
Google Docs: https://drive.google.com/file/d/0B1fu729GXZJyY3RkX3ZNVlp5QjA/view
Excel File: NiMH_Capacity_Analysis-Scott_Dotdot-20170908.xlsx
My Recommendation
Not to spoil the video, but if you’re here for a recommendation: At the current price of $21.99 for a sixteen pack, the EBL 2300mAh cells are the way to go. However, I’d also recommend the high capacity cells by Amazon and Sunlabz.
I own a bunch of Panasonic Eneloop cells, and they are reliable, well made, and meet or exceed their advertised capacity. I’d absolutely recommend Eneloops or Eneloop Pros, at the right price. They can be catastrophically expensive, which is the only reason they aren’t my first recommendation. The EBL and Sunlabz cells give much better value for money.
Update (2017-09-08):
Tenergy was kind enough to get in touch after having seen my review, and I’d be remiss if I didn’t pass on a couple of their corrections:
First of all, I’d like to say that I really appreciate your review. It is one of the most extensive reviews I’ve seen. Regardless how our products stack up against the competitors in the market, I am grateful that Tenergy have been selected to compete against Duracell/Energizer/Eneloop, the giants in the battery industry. That being said, there is one correction I’d like to make in your review, the Tenergy Centura AA battery NiMH batteries you tested are actually rated/labeled 2000mAh, not 2200mAh as stated in your review. This correction would bring the actual capacity vs. stated capacity ratio to 91% instead of 83%.
This is, of course, 100% accurate. I’m not sure where I found (or possibly why I invented) the 2200mAh number, but regardless I apologize to Tenergy for the mistake. Though I can’t correct a video once it’s on YouTube, I updated the related spreadsheet (linked above) and made a note in the description to reflect the correct number.
Their representative goes on to say:
Though, just one last thing, stated capacity of NiMH batteries is from testing at 0.2C discharge rate. This is same for Energizer, Panasonic, and Duracell. It’s somewhat of an industry standard even though some Duracell datasheets show testing at 0.1C. This kind of throws things off a little when you test different capacity cells at the same discharge rate because 0.2C for 2000mAh is 400mA and for a 2700mAh is 540mA so you will always get different results from their stated capacity when testing this way.
Fair enough, I suppose.
The video is a bit long (to say the least), but at the end I did address that my testing methodology probably diverged from the various manufacturers’ testing methods. Call me cynical, but I only pay lip service to their testing.
This is because 1) I’d have difficulty believing that manufacturers don’t design and execute their own tests in a manner that would prove favorable to their own product, and 2) real-world use cases are very rarely (or almost never) going to match the discharge conditions presented in a laboratory. My testing was surely flawed, but it is also surely a representation of the various cells at the conditions I put upon them. My test will obviously also not universally represent real-world conditions. If I’d had more time I would’ve liked to repeat the discharge tests at various other currents, temperatures, as well as before and after numerous cycles.
At any rate, I appreciate Tenergy’s interest in the video and the pride they take in their product! They were also exceedingly polite about the whole thing.
I suppose as an epilogue of sorts I should mention that the 4 Tenergy batteries in my collection are still going strong now, a year later.
